Egg yolk is the yellow, nutrient-rich center of an egg. It is surrounded by egg white and enclosed within the eggshell. Egg yolk is a concentrated source of vitamins, minerals, and fats, including essential nutrients such as vitamin A, vitamin D, and choline. It is commonly used in cooking and baking to add richness, flavor, and moisture to dishes. Egg yolks can be cooked in various ways, such as scrambled, poached, or hard-boiled, and are a versatile ingredient in a wide range of recipes.